It also contains peptone which acts as a source of nitrogen (remember that whenever peptone is utilized under aerobic condition, ammonia is produced).Īddition of sucrose in TSI agar permits earlier detection of coliform bacteria that ferment sucrose more rapidly than lactose.Phenol red: Indicator of acidification (It is yellow in acidic conditions and red under alkaline conditions).Iron (ferrous sulfate): Indicator of H 2 S formation.So the appearance of yellow color in both slant and butt indicates that the isolate has the ability to ferment lactose or sucrose or both. 1.0 % lactose/1.0% sucrose: If lactose or sucrose or both sugars are fermented, a large amount of acid will produce which turns both butt and slant yellow.0.1% glucose: If only glucose is fermented, only enough acid is produced to turn the butt yellow. The slant will remain red.TSI is similar to Kligler’s iron agar (KIA), except that Kligler’s iron agar contains only two carbohydrates: glucose (0.1%) and lactose (1%). 10 part lactose (1%), 10 part sucrose (1%) and 1 part glucose (0.1%)). Lactose, sucrose and glucose are in the concentration of 10:10:1 (i.e. Results of Triple Sugar Iron (TSI) Agar Tests Composition of TSI Agarġ0.0 g Sucrose 10.0 g Ferrous sulfate or ferrous ammonium sulfate 0.2 g NaCl 5.0 g Sodium thiosulfate 0.3 g Phenol red 0.024 g Agar.
0 kommentar(er)
